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Preparation method of 3-nitro-N-ethyl carbazole

A technology of ethylcarbazole and nitrocarbazole, which is applied in the field of preparation of 3-nitro-N-ethylcarbazole, achieves the effects of high conversion rate, low occupational hazard and simple process

Inactive Publication Date: 2013-08-21
NANTONG LONGXIANG NEW MATERIALS TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The method for preparing 3-nitro-N-ethylcarbazole through N-ethylation about 3-nitrocarbazole has not yet been reported

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] Put 600g of 30% sodium hydroxide solution, 100g of 3-nitrocarbazole, 5g of polyethylene glycol, and 59.07g of ethyl bromide into a three-necked flask with a stirring and reflux condenser, and slowly heat up to 35°C. The reaction continues to heat up, and the control temperature is always lower than the boiling point of the system. When the conversion rate of 3-nitrocarbazole reaches more than 99.5%, the reaction is considered to be over. After cooling and crystallization, filtration, washing and drying, 3-nitro-N-ethyl Carbazole solid, yield 97.7%.

Embodiment 2

[0015] Put 400g of 40% sodium hydroxide solution, 100g of 3-nitrocarbazole, 2.18g of polyethylene glycol, 0.55g of benzyltriethylammonium chloride, 0.27g of ethanol, and 56.50g of ethyl bromide into the belt with stirring and In the three-necked flask of the reflux condenser, slowly heat up to 35°C, and continue to heat up as the reaction progresses. The temperature is always lower than the boiling point of the system. When the conversion rate of 3-nitrocarbazole reaches more than 99.5%, the reaction is considered to be over. After cooling and crystallization , filtered, washed, and dried to obtain 3-nitro-N-ethylcarbazole as a solid, with a yield of 98.1%.

Embodiment 3

[0017] Put 300g of 40% sodium hydroxide solution, 100g of 3-nitrocarbazole, 0.83g of polyethylene glycol, 0.83g of benzyltriethylammonium chloride, 0.34g of ethanol, and 53.93g of ethyl bromide into the belt with stirring and In the three-necked flask of the reflux condenser, slowly heat up to 35°C, and continue to heat up as the reaction progresses. The temperature is always lower than the boiling point of the system. When the conversion rate of 3-nitrocarbazole reaches more than 99.5%, the reaction is considered to be over. After cooling and crystallization , filtered, washed, and dried to obtain 3-nitro-N-ethylcarbazole as a solid, with a yield of 98.5%.

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Abstract

The invention discloses a preparation method of 3-nitro-N-ethyl carbazole, which is characterized by comprising the following steps: putting a sodium hydroxide solution, 3-nitro carbazole, a catalyst, part or all of ethyl bromide into a three-necked flask with a stirring and reflux condenser, slowly heating the obtained object to 35-40 DEG C, and dropwise adding the rest of ethyl bromide into the flask at the temperature; after the dropwise adding is completed, carrying out heating on the obtained mixture with the reaction, and controlling the temperature to be always below a boiling point of a system; determining that the reaction is completed when the 3-nitro carbazole conversion rate reaches more than 99.5%; carrying out cooling crystallization, filtration, washing and drying on the obtained product so as to obtain 3-nitro-N-ethyl carbazole. The method disclosed by the invention has the advantages that benzene is added as a solvent in general alkylation reactions, but no benzene is added in the invention, therefore, the application amount of ethyl bromide is relatively less, so that the method is simple in process, high in conversion rate and small in occupational hazards.

Description

technical field [0001] The invention relates to a preparation method of 3-nitro-N-ethylcarbazole, which belongs to the field of chemical industry. Background technique [0002] 3-Nitro-N-ethylcarbazole is an important intermediate in the synthesis of high-grade organic pigments permanent violet RL. N-ethylcarbazole is produced by reacting carbazole with ethyl bromide under the action of a phase transfer catalyst, and then It is prepared by nitration of dilute nitric acid, and the two-step total yield does not exceed 75%. This method is limited by the source of carbazole and the synthesis yield. If 3-nitrocarbazole can be synthesized with non-carbazole raw materials by chemical method, and then ethylated to prepare 3-nitro-N-ethylcarbazole, it will not only get rid of the dependence of the original process on raw material carbazole, but also The reaction yield can be improved through optimization. There is no report about the method of preparing 3-nitro-N-ethylcarbazole thr...

Claims

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Application Information

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IPC IPC(8): C07D209/88
Inventor 倪伟
Owner NANTONG LONGXIANG NEW MATERIALS TECH CO LTD
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